Combination cable guard and centralizer device for use with downhole tubing strings

ABSTRACT

A combination cable guard and centralizer device, comprising an arcuate-shaped elongate base member having tapered ends, a pair of first hinge-housing portions wherein each of said pair is at an opposite end of a first elongate edge, and an opposite first elongate edge has a pair of spaced-apart channels for receiving and demountably engaging therein a shank portion and a flanged head portion of a bolt, and (ii) a complementary arcuate-shaped elongate upper member having tapered ends, a second hinge-housing portion in rotational hinged communication with the pair of first hinge-housing portions. The upper member has a second pair of channels for rotationally receiving therein a cylindrical rod having a female-threaded bore therethrough, and a third set of channels for receiving therethrough a male-threaded portion of the bolt wherein the male-threaded bolt is threadably engaged with the female-threaded bore of the cylindrical rod.

TECHNICAL FIELD

This disclosure generally relates to downhole tubing strings used for recovery of hydrocarbons from oil and/or gas wells. More particularly, the disclosure pertains to demountable cable guards for concurrently securing a plurality of electrical cables adjacent to a downhole tubing string and for centralizing the tubing string in a wellbore.

BACKGROUND

Recovery of hydrocarbons from an oil and/or a gas well relies on the use of an electrical submersible pump (ESP) positioned at the bottom of a well bore adjacent to or within a subterranean hydrocarbon reservoir, to pressurize and pump the hydrocarbons to the surface. A wellbore typically comprises an outer casing that extends from the surface to the bottom of the wellbore. A tubing string extending from the bottom of the wellbore to the surface, is housed within the casing and is the conduit for flowing the ESP-pressurized hydrocarbons to the surface. A plurality of armored electrical cables are provided for supplying electrical power to the ESP and for controlling the operation of the ESP. In addition to the electrical cables in communication with the ESP, wellbores also house a variety of other electrical cables and/or fiber optic cables in the space between the casing and the tubing string. Such cables may be in communication with pressure sensors, temperature sensors, seismic sensors, other such monitoring systems, and the like. One or more hydraulic lines to operate valves, or to set packers, and other such operations, may be housed in the space between the casing and the tubing string. In addition, the space between the casing and the tubing string may also house additional lift systems for increased recovery of hydrocarbons from an oil and/or a gas well. Consequently, a wellbore typically contains a number of cables and lines that extend downward in the space between the casing and the downhole tubing.

It is common practice to secure a plurality of downhole cables to the tubing string with removable elongate clamps that have internal channels for housing therein one or more cables. Such clamps are commonly known as “cable guards”. Most cable guards comprise two hinged-together components wherein one component is a base member that extends along one side of the tubing string and the other component is a clamp member that extends along the opposite side of the tubing string. The base member typically has an internal channel extending along its longitudinal axis while the corresponding clamp member may or may not have an internal channel extending along its longitudinal axis. Such cable guards are typically deployed downhole in an open position, and at a selected location, one or more cables are maneuvered into the internal channel of the base member which is then positioned against the side of the tubing string. The open end of the clamp member is then positioned against the other side of the tubing string and biased toward the open end of the base member. The two open ends are then bolted together. Some prior art cable guards employ snap-lock mechanisms for engagement of the open ends of the base member and clamp member.

It is common for large numbers of cable guards to be mounted along the length of a tubing string for securing thereagainst a plurality of cables and lines. There are however, many problems with the current cable guards available for use. There is considerable pressure and torsion within and about a tubing string as a consequence of the operation of the ESP and the pressurized flow of hydrocarbons from the bottom of the wellbore to the surface. These forces cause the tubing string to twist about and move back and forth within the casing causing compressive abrasion of the cable guard resulting in metal fatigue, wear, and breakage. Such compromised cable guards must be replaced in order to adequately protect the cables resident in the wellbore. Many current cable guards comprise solid base and clamp members and consequently, are expensive, heavy, and difficult to maneuver and secure downhole. Furthermore, the use of nuts and bolts, or alternatively, snap-locks to securely engage and to disengage the open ends of the base and clamp members make the installation and removal processes complicated and cumbersome.

SUMMARY

The embodiments of the present disclosure generally relate to a combination cable guard and centralizer device for housing and securing therein electrical cables that extend alongside a tubing string. The cable guard and centralizer device comprises an elongate base member and a complementary elongate upper member that are hingedly connected along one elongate side. The opposite elongate open end of the base member is fitted with two self-retaining bolt assemblies wherein one self-retaining bolt assembly is positioned approximate the proximal end and the second self-retaining bolt assembly is positioned approximate the distal end of the elongate open end.

The self-retaining bolt assemblies comprise a head at their proximal end from which extend a shank portion followed by a male-threaded portion to their distal end. The distal end of the self-retaining bolt is threaded into a cylindrical lug having a female-threaded bore therethrough wherein the female-threaded bore is at 90° to the longitudinal axis of the cylindrical lug. Each cylindrical lug is inserted into channel provided therefore approximate the proximal or distal end of the elongate open end of the base member, after which, the proximal male-threaded end of a self-retaining bolt is threadingly engaged with a female-threaded bore in a cylindrical lug. The cylindrical lug is rotatable within the channel provided therefore, thereby enabling the self-retaining bolt to swivel back and forth about the elongate open end of the base member.

The opposite elongate open end of the upper member may have two receptacles. One receptacle is approximate the proximal end and the other receptacle is approximate the distal end of the elongate open end of the elongate open end of the upper member. Each receptacle of the upper member is configured to receive therein the shank of a self-retaining bolt and to retainingly engage the undersurface of the bolt head. The heads of the self-retaining bolts engaged with the open end of the base member may be demountably engaged with the receptacles provided therefore on the elongate open end of the upper member. The complimentary open ends of the base and upper members can be drawn together by threadably engaging the self-retaining bolts within the female-threaded bores within the cylindrical lugs.

The inner-facing surface of the base member may have three knurled sections projecting outward therefrom for engaging the outer surface of the tubing string and preventing rotation of the combination cable guard and centralizer about the tubing string during installation. The upper member has three sections, a distal section, a middle section, and a proximal section. The middle section is cast with a flat surface at the contact point which is be machined to receive therein specific cables and accessories.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will be described in conjunction with reference to the following drawings, in which:

FIG. 1A is a perspective view of an embodiment of the combination cable guard and centralizer devices disclosed herein, shown in a closed and engaged position, while FIG. 1B is a perspective view of the device shown in an open position;

FIG. 2A is a side view of the elongate base member of the device shown in FIGS. 1A and 1B, while FIG. 2B is a bottom view of the elongate base member;

FIG. 3A is a longitudinal cross-sectional inward-facing view of the elongate base member shown in FIGS. 2A and 2B, while FIG. 3B is a cross-sectional side view of the elongate base member;

FIG. 4A is a top view of the complementary elongate upper member, while FIG. 4B is a longitudinal view of the inside of the elongate upper member shown in FIG. 4A;

FIG. 5A is a side view of the elongate upper member shown in FIGS. 4A and 4B, FIG. 5B is an end view of the elongate upper member, and FIG. 5C is a cross-sectional end view of the elongate upper member;

FIG. 6A is a perspective view of a self-retaining bolt assembly according to another embodiment of the present disclosure, while FIG. 6B is a side view of the self-retaining bolt assembly shown in FIG. 6A;

FIG. 7 is a side view of the combination cable guard and centralizer device illustrated in FIGS. 1 to 6, shown engaged around a tubing string and a plurality of cables;

FIG. 8A is an end view of the combination cable guard and centralizer device engaged around a tubing string and a plurality of cables shown in FIG. 7, while FIG. 8B is a cross-sectional end view of the combination cable guard and centralizer device engaged around a tubing string and a plurality of cables shown in FIG. 8A;

FIG. 9A is a perspective view of another embodiment of the combination cable guard and centralizer devices disclosed herein, shown in a closed and engaged position, while FIG. 9B is a perspective view of the device shown in an open position;

FIG. 10 is a side view of the combination cable guard and centralizer device illustrated in FIGS. 9A and 9B, shown engaged around a tubing string and a plurality of cables;

FIG. 11 is an end view of the combination cable guard and centralizer device engaged around the tubing string and the plurality of cables, shown in FIG. 10;

FIG. 12A is a side view of an embodiment of a collar for use with the combination cable guard and centralizer devices disclosed herein, while FIG. 12B is a top view of the collar;

FIG. 13A is a side view of another embodiment of a collar for use with the combination cable guard and centralizer devices disclosed herein, while FIG. 13B is a top view of the collar;

FIG. 14A is a perspective view of another embodiment of the combination cable guard and centralizer devices disclosed herein, shown in an open position, while FIG. 1B is end view of the combination cable guard and centralizer device shown in a closed position; and

FIG. 15A is a top view of the combination cable guard and centralizer device from FIGS. 14A and 14B shown in a closed position, while FIG. 15B is a side view of the combination cable guard and centralizer device.

DETAILED DESCRIPTION

The present disclosure relates to combination cable guard and centralizer units for demountable engagement about downhole tubing strings positioned within oil and gas wellbores. The combination guard and centralizer units are configured for housing and securing therebetween the combination guard and centralizer units and the downhole tubing string, a plurality of electrical cables and/or fiber optic cables and /or other types of narrow-diameter conduits that may be deployed in a wellbore alongside a downhole tubing string. Each of the combination guard and centralizer units disclosed herein comprise two complementary elongate elements that are hinged together along one side so that the units can be opened and closed in a clam-shell fashion. The two complementary elongate elements are provided with demountable engagement components on their sides opposite their hinged-together sides whereby the combination guard and centralizer units can be closed and securely engaged together by the engagement components.

Some embodiments of the combination guard and centralizer units disclosed herein are configured for ease of insertion into and deployment within a wellbore adjacent to a downhole tubing string while in a hinged-open position for encircling a plurality of cables and/or conduits that were deployed adjacent to the downhole tubing string for connection with various types of tools and/or instruments and/or sensing/monitoring devices required for operation of the downhole tubing string within the wellbore, after which, the combination guard and centralizer units may be manipulated to selectively position each of the plurality of cables and/or conduits in channels provided therefor on the inner surfaces of the combination guard and centralizer units, after which, the combination guard and centralizer units can be manipulated into a hinged-closed position while encircling the tubing string and the adjacent plurality of cables and/or conduits, and then securely engaged together with the engagement components to clamp and lock the combination guard and centralizer units and the plurality of cables and/or conduits to the downhole tubing string. If so desired at a later to date to service and/or remove one or more of the tools and/or instruments and/or sensing/monitoring devices interconnected with the plurality of cables and/or conduits that are encircled by the combination guard and centralizer units, then the engagement components that secured the combination guard and centralizer units in the hinged-closed position can be disengaged so that the combination guard and centralizer units can be moved into a hinged-open position whereby one or more of the plurality of cables removed from between the downhole tubing string and the combination guard and centralizer units for service or replacement or permanent removal. After the service work has been completed, the combination guard and centralizer units may be repositioned about the plurality of cables and/or conduits, after which, the combination guard and centralizer units can be manipulated into a hinged-closed position while encircling the tubing string and the adjacent plurality of cables and/or conduits, and then securely engaged together with the engagement components to clamp and lock the combination guard and centralizer units and the plurality of cables and/or conduits to the downhole tubing string.

Some embodiments of the combination guard and centralizer units disclosed herein comprise shockproof and/or shock-resistant materials to protect an encircled plurality of cables and/or conduits from physical damage from movements of the downhole tubing string about and within wellbores during operation.

Some embodiments of the combination guard and centralizer units disclosed herein comprise gripping elements provided on the inner surfaces of the two complementary elongate elements that comprise each combination guard and centralizer unit.

One example disclosed herein of a light-weight but structurally durable combination cable guard and centralizer device 10 for housing and securing therein electrical cables that extend alongside a tubing string, is illustrated in FIGS. 1-8. The combination guard and centralizer devise 10 comprises an elongate base member 12 and a complementary elongate upper member 40 that are designed to demountably encircle and engage around a downhole tubing string and a plurality of electrical cables and/or wiring and/or conduits, and the like. The elongate base member 12 and complementary elongate upper member 40 are hinged together along one of their elongate sides so that combination guard and centralizer devise 10 can be opened and closed in a clam-shell fashion.

The elongate base member 12 is shown in FIGS. 2, 3, and comprises a generally arcuate-shaped elongate base body 13 with tapered ends 14. Two pairs of orifices 20 defined by side walls 20 a are machined through the elongate base body 13 to reduce the weight of the elongate body 13 while maintaining its structural integrity and durability. The outward-facing inner surface of the elongate base body 13 has two or more sets of knurled projections 24 and/or ridged projections 26 extending therefrom, wherein each set of knurled projections 24 extends from one end of the elongate base body 13 to the other end of the elongate body 13. The sets of knurled projections 24 and ridged projections 26 may extend from one end of the elongate base body 13 to the other end. Alternatively, one or more of the sets of knurled projections 24 and ridged projections 26 may extend only partially from one end of the elongate base body 13 toward the other end. A set of knurled projections may comprise repeating conical projections, spherical projections, spheroid projections, ellipsoid projections, pyramidal projections, and the like. Alternatively, a set of ridged projections may comprise repeating elongate prism-shaped projections, elongate wedge-shaped projections, elongate quonset-shaped projections, and the like.

One elongate edge of the elongate base member 12 may have a hinge-pin housing element 28 at each end of the elongate base body 13 with a bore 30 therethrough each hinge-pin housing element 28 for receiving therethrough a hinge pin 31 (shown in FIG. 8A). The opposite elongate edge 29 of the elongate base member 12 has two channels 16 extending vertically therethrough with one channel 16 located near each end of the elongate base member 12. A channel 18 extends laterally into and through channel 16 from each end of the elongate base member 12. A longitudinally extending channel 22 may be provided within the inward-facing surface of the elongate base member 12 for receiving and housing therein an electrical cable or optionally an electrical line, or optionally, a hydraulic line.

The complementary elongate upper member 40 is shown in FIGS. 4, 5, and comprises a generally arcuate-shaped elongate upper body 42 with tapered ends 44. Two pairs of matching orifices 46 defined by side walls 46 a are machined through the opposite sides of the elongate upper body 42 to reduce the weight of the elongate upper body 42 while maintaining its structural integrity and durability. A third pair of orifices 48 defined by side walls 48 a is machined through the top section of the arcuate-shaped elongate upper body 42, whereby the third pair of top orifices 48 is interposed equidistantly between the two pairs of side orifices 46. The three pairs of orifices 46, 46 substantially reduce the weight of the weight of the elongate upper body 42 while maintaining its structural integrity and durability. The outward-facing inner surface of the elongate upper body 42 has two sets of knurled projections 26 extending partially from each end of the elongate upper body 42 toward the other end. As shown in FIG. 4B, the sets of knurled projections 26 on the inner surface of elongate upper body 42 may comprise repeating elongate prism-shaped projections, elongate wedge-shaped projections, elongate quonset-shaped projections, and the like. Alternatively, the sets of knurled projections 26 on the inner surface of elongate upper body 42 may comprise repeating conical projections, spherical projections, spheroid projections, ellipsoid projections, pyramidal projections, and the like.

One elongate edge of the elongate upper member 40 may have a hinge-pin housing element 48 (FIGS. 4B, 5A) that fits in between the hinge-pin housing elements 28 at each end of the elongate base body 13 (FIGS. 2B, 3A). The hinge-pin housing element 48 has a bore 30 therethrough (FIG. 4B) that is aligned with the bores 30 in hinge-pin housing element 28 (FIG. 2B) for receiving therethrough a hinge pin 31 (shown in FIG. 8A). The opposite elongate edge 49 of the elongate upper body 42 has two channels 50 extending vertically therethrough with one channel 50 located near each end of the elongate upper member 40. Each channel 50 comprises a narrower first bore 50 b extending upward from the bottom of elongate edge 49, and a wider second bore 50 a extending upward from a shoulder 50 c at the terminus of the first bore 50 b (FIG. 5A).

A plurality of longitudinally extending channels may be provided within the inward-facing surface of the elongate upper body 42 thereby providing a contoured inner surface. For example, this embodiment has three side-by-side channels 52, 54, 56 wherein the center channel 52 is configured to receive and retain therein an electrical cable for providing power to an ESP (FIGS. 4B, 5B, 5C). Channels 54, 56 on either side of channel 52 have narrower diameters and profiles that are suitable for receiving and retaining therein one or more cables communicating with sensors or instruments, or alternatively, for receiving and retaining there in a hydraulic line.

An example of a self-retaining bolt assembly 70 disclosed herein for demountably engaging (i) channels 16, 18 in the elongate base member 12, and (ii) channels 50 in the complementary elongate upper member 40 is shown in FIG. 6. The self-retaining bolt assembly 70 comprises a cylindrical rod 70 f with a female-threaded bore therethrough the side of the cylindrical rod 70 f. The cylindrical rod is configured to slide into channel 18 provided therefore in the elongate base member 12, and then to rotate therein. The bolt component comprises at its proximal end, a head 70 a with a built-in washer 70 b (or alternatively, a flanged head), a shank portion 70C extending into a male-threaded portion 70 d. The distal end of the bolt component is provided with a channel for receiving and housing therein a retainer ring 70 e. The self-retainer bolt assembly may be installed into the elongate base member 12 as follows. First, the cylindrical rod 70 f is inserted into channel 16. Then, the male-threaded portion 70 d of the bolt component is threadably engaged with the female-threaded bore in the cylindrical rod 70 f until the distal end of the bolt component extends sufficiently through the cylindrical rod 70 f so that a retainer ring can be snapped into the channel provided therefore in the distal end of the bolt component. The retainer ring prevents accidental rotational removal of the bolt component out of the cylindrical rod 70 f.

The combination cable guard and centralizer device 10 disclosed herein may be assembled by inserting the hinge-pin housing element 48 of the elongate upper member 40 (FIGS. 4B, 5A) in between the hinge-pin housing elements 28 at each end of the elongate base body 13 (FIGS. 2B, 3A), and then inserting a hinge pin in through the bores 30 provided therefore in the hinge-pin housing elements 28, 48 thereby enabling a clam-shell type opening and closing of the combination cable guard and centralizer device 10 as illustrated in FIGS. 1A, 1B. When the elongate upper member 40 and the elongate base member 12 are in a closed position (FIG. 1B), the self-retaining bolt assemblies 70 may be swiveled into channels 50 so that the built-in washer 70 b of the head 70 a (FIG. 6) is positioned over the shoulders 50 c at the terminus of the first bores 50 b of the channels 50 (FIG. 5A). The bolt components of the self-retaining bolt assemblies 70 may then be rotationally threadably engaged with the female-threaded bores of the cylindrical rods 70 e).

FIGS. 7 and 8 illustrate the combination cable guard and centralizer device 10 installed onto a tubing string 80 whereby the device 10 has secured and compressed electrical cables 82, 84, 86 and line 88 against the tubing string 80. The tapered ends 14, 44 of the elongate base member 12 and elongate upper member 40 facilitate introduction of the combination cable guard and centralizer device 10 into a wellbore and its delivery, in an open position, to a target engagement location about the tubing string. At the target location, the combination cable guard and centralizer device 10 is urged against the tubing string 80 and a line 88 which is urged into channel 22 in the elongate base body 13. The sets of knurled projections 24, 26 on the inner face of the elongate base body 13 prevent slippage and rotation of the combination cable guard and centralizer device 10 about the tubing string 80 as the electrical cables 82, 84, 86, are maneuvered into the channels 52, 54, 56 in the inner face of the elongate upper body 42. After the cables are in the channels, then the self-retaining bolt assembles are swiveled into position in channels 50 and then tightened to securely engage the combination cable guard and centralizer device 10 to the tubing string. It should be noted that (i) the outward-facing longitudinal edges of the hinge-pin housing element 28 at each end of the elongate base body 13 and the opposite elongate edge 29, and (ii) the outward-facing edges of the hinge-pin housing element 48 and the opposite elongate edge 49 of the elongate upper body 42, are lipped outward (best seen in FIGS. 8A, 8B). Additionally, an outward-protruding longitudinal ridge 62 is provided along the center of the outer surface the elongate upper body 42. These protuberances centralize the combination cable guard and centralizer device 10, the tubing string 80, and the electrical cables and lines 82, 84, 86, 88 securely engaged therein.

Oil and gas wells are produced or measured using various tubing types and sizes depending on what is required from the well. These include creating a conduit for oil and gas to flow to surface, installing and hanging lift equipment, deployment of tools and sensors for measuring the characteristics of downhole wellbores. The common factors to choosing a tubing type and size are as such. Wellbore casing and wellhead size, weight of equipment hanging off the end of the tubing, pressure rating, corrosion and abrasion resistance and cost. In addition to selecting the tubing type operators also have various coupling types to go along with each tubing type. Accordingly, the combination cable guard and centralizer devices disclosed herein may be sized to demountably engage any diameter of tubing selected for downhole installation in an oil or gas well, and to secure adjacent to the tubing, one or more conduits. For example, the combination cable guard and centralizer device may be sized to demountably engage a tubing having an outside diameter of 1.5 in., 2.0 in., 2.5 in., 3.0 in., 3.5 in., 4.0 in., 4.5 in., 5.0 in., 5.5 in., 6.0 in., 6.5 in., 7.0 in., 7.5 in., 8.0 in., 8.5 in., 9.0 in., 9.5 in., 10.0 in., 10.5 in., 1.0 in. (i.e., 38 mm, 50.8 mm, 63.5 mm, 76.2 mm, 88.9 mm, 101.6 mm, 114.3 mm, 127 mm, 139.7 mm, 152.4 mm, 165.1 mm, 177.8 mm, 190.5 mm, 203.2 mm, 215.9 mm, 228.6 mm, 241.3 mm, 254 mm, 266.7 mm, 279.4 mm), and therebetween, and to secure adjacent to the tubing, one or more service conduits.

Another example 100 of the combination cable guard and centralizer devices disclosed herein is illustrated in FIGS. 9-12 is illustrated in FIGS. 1-8. The combination guard and centralizer devise 100 comprises an elongate base member 112 and a complementary elongate upper member 140 that are designed to demountably encircle and engage around a downhole tubing tubing and a plurality of electrical cables and lines. The elongate base member 112 and complementary elongate upper member 140 are hinged together along one of their elongate sides so that combination guard and centralizer devise 100 can be opened and closed in a clam-shell fashion.

The elongate base member 112 comprises a generally arcuate-shaped elongate base body with tapered ends 114. A pair of orifices ‘20 defined by side walls 120 a is machined through the elongate base member 112 to reduce the weight of the elongate member 112 while maintaining its structural integrity and durability. The outward-facing inner surface of the elongate base member 112 has two or more sets of knurled projections 124 and/or ridged projections 126 extending therefrom, wherein each set of knurled projections 124 extends from one end of the elongate base member 112 to the other end of the elongate member 112. The sets of knurled projections 124 and ridged projections 26 may extend from one end of the elongate base member 112 to the other end. Alternatively, one or more of the sets of knurled projections 124 and ridged projections 126 may extend only partially from one end of the elongate base member 112 toward the other end. A set of knurled projections may comprise repeating conical projections, spherical projections, spheroid projections, ellipsoid projections, pyramidal projections, and the like. Alternatively, a set of ridged projections may comprise repeating elongate prism-shaped projections, elongate wedge-shaped projections, elongate quonset-shaped projections, and the like.

One elongate edge of the elongate base member 112 may have a hinge-pin housing element 128 at each end with a bore therethrough for receiving therethrough a hinge pin 131 (shown in FIG. 11). The opposite elongate edge of the elongate base member 112 has a channel 116 extending vertically therethrough at approximately the midpoint of the elongate base member 112. A channel 118 extends laterally into and through channel 116 from the end of the elongate base member 112. A longitudinally extending channel 122 may be provided within the inward-facing surface of the elongate base member 112 for receiving and housing therein an electrical cable or optionally an electrical line, or optionally, a hydraulic line.

The complementary elongate upper member 140 comprises a generally arcuate-shaped elongate upper body 1 with tapered ends 144. A pair of matching orifices 146 defined by side walls 146 a are machined through the opposite sides of the elongate upper member 140 to reduce the weight of the elongate upper member 140 while maintaining its structural integrity and durability. The outward-facing inner surface of the elongate upper member 140 has two sets of knurled projections 126 extending partially from each end of the elongate upper member 140 toward the other end. As shown in FIG. 4B, the sets of knurled projections 126 on the inner surface of elongate upper member 140 may comprise repeating elongate prism-shaped projections, elongate wedge-shaped projections, elongate quonset-shaped projections, and the like. Alternatively, the sets of knurled projections 126 on the inner surface of elongate upper member 140 may comprise repeating conical projections, spherical projections, spheroid projections, ellipsoid projections, pyramidal projections, and the like.

One elongate edge of the elongate upper member 140 may have a hinge-pin housing element 148 that fits in between the hinge-pin housing elements 128 at each end of the elongate base member 112. The hinge-pin housing element 148 has a bore therethrough that is aligned with the bores in hinge-pin housing element 128 for receiving therethrough a hinge pin 131 (shown in FIG. 11). The opposite elongate edge of the elongate upper member 140 has a channel 150 extending vertically therethrough at approximately the midpoint of the elongate upper member 140. The channel 50 comprises a narrower first bore extending upward from the bottom of elongate edge, and a wider second bore extending upward from a shoulder at the terminus of the first bore.

A plurality of longitudinally extending channels may be provided within the inward-facing surface of the elongate upper member 140. For example, this embodiment has one centered channel 145 to receive and retain therein an electrical cable for providing power to an ESP along one or more cables communicating with sensors or instruments, or alternatively, for receiving and retaining there in a hydraulic line.

FIGS. 10 and 11 illustrate the combination cable guard and centralizer device 100 installed onto a tubing string 180 whereby the device 100 has secured and compressed electrical cables 182, 184, 186 and line 188 against the tubing string 180. The tapered ends 114, 144 of the elongate base member 112 and elongate upper member 140 facilitate introduction of the combination cable guard and centralizer device 100 into a wellbore and its delivery, in an open position, to a target engagement location about the tubing string. At the target location, the combination cable guard and centralizer device 100 is urged against the tubing string 180 and a line 188 which is urged into channel 122 in the elongate base member 112. The sets of knurled projections 124, 126 on the inner face of the elongate base member 112 prevent slippage and rotation of the combination cable guard and centralizer device 100 about the tubing string 180 as the electrical cables 182, 184, 186, are maneuvered into the channels 145 in the inner face of the elongate upper member 140. After the cables are in the channels, then the self-retaining bolt assembles are swiveled into position in channel 145 and then tightened to securely engage the combination cable guard and centralizer device 100 to the tubing string.

Another embodiment of the present disclosure pertains to collars configured for mating engagement with the inner surface of the elongate base member or alternatively, with the complementary elongate upper member of the combination cable guard and centralizer devices disclosed herein.

In some production field settings, it may be desirable to demountably and securely engage the combination cable guard and centralizer device to tubing having a smaller outside diameter than the inside diameter of the combination cable guard and centralizer device. Accordingly, another embodiment of the present disclosure pertains to collars configured for mating engagement with the inner surface of the elongate base member or alternatively, with the complementary elongate upper member of the combination cable guard and centralizer devices disclosed herein, wherein the collars are compressible between the inner surfaces of the combination cable guard and centralizer devices and the outer surfaces of the smaller-diameter tubing. The collars may comprise a compressible material, laminations of one or more compressible materials, resilient materials, and the like. Examples of suitable materials include, but are not limited to, soft metals, plastics, rubbers, polymers, and the like.

An example of a suitable collar 90 according to the present disclosure is shown in FIGS. 12A and 12B. The collar 90 comprises two downward extending legs 90 a bridged together by a shoulder portion 90 b. The outer-facing surface of the collar 90 is configured to matingly engage, in this example, with the inner-facing surfaces 26, 52, 54, 56 of the elongate upper member 40 of the combination cable guard and centralizer device 10 illustrated in FIGS. 1-8 (the inner-facing surfaces 26, 52, 54, 56 are shown in FIGS. 5B and 5C). The shoulder portion 90 b of collar 90 has a predetermined thickness while the thickness of the legs 90 a may be the same as the thickness or the shoulder 90 b, or alternatively if so desired for certain types of applications, may be thicker than or thinner than the thickness of the shoulder portion 90 b. The thickness of the shoulder portion 90 b may be ¼ in., ½ in., ¾ in., 1 in. (i.e., 6.35 mm, 12.7 mm, 19.05 mm, 25.4 mm), and therebetween. The collar 90 may be provided with one or more bores 94 through the shoulder portion 90 b that are aligned with bores 47 provided in the elongate upper member 40 (refer to FIGS. 4A, 4B, 5B, 8B) to facilitate affixing of the collar 90 to the elongate upper member 40, for example with screws or bolts or rivets and the like.

Another example of a suitable collar 95 according to the present disclosure is shown in FIGS. 13A and 13B. The collar 95 comprises two downward extending legs 95 a bridged together by a shoulder portion 95 b. The outer-facing surface of the collar 95 is configured to matingly engage, in this example, with the inner-facing surfaces 122, 145 of the elongate upper member 140 of the combination cable guard and centralizer device 100 illustrated in FIGS. 9-11 (the inner-facing surfaces 122, 145 are shown in FIG. 11). The shoulder portion 95 b of collar 95 has a predetermined thickness while the thickness of the legs 95 a may be the same as the thickness or the shoulder 95 b, or alternatively if so desired for certain types of applications, may be thicker than or thinner than the thickness of the shoulder portion 95 b. The thickness of the shoulder portion 95 b may be ¼ in., ½ in., ¾ in., 1 in. (i.e., 6.35 mm, 12.7 mm, 19.05 mm, 25.4 mm), and therebetween. The collar 95 may be provided with one or more bores 99 through the shoulder portion 95 b that are aligned with bores (not shown) provided in the elongate upper member 140 to facilitate affixing of the collar 95 to the elongate upper member 140, for example with screws or bolts or rivets and the like.

Another example of light-weight but structurally durable combination cable guard and centralizer devices according to the present disclosure for housing and securing therein cables and conduits that extend alongside a downhole tubing string disposed with in a wellbore is shown in FIGS. 14A, 14B, 15A, and 15B. The combination guard and centralizer devise 200 comprises an elongate base member 212 and a complementary elongate upper member 240 that are designed to demountably encircle and engage around a downhole tubing string and a plurality of adjacent cables and/or conduits interconnected with equipment and/or instruments and/or monitoring devices, and the like. The elongate base member 212 and complementary elongate upper member 40 are hinged together along one of their elongate sides so that combination guard and centralizer devise 200 can be opened and closed in a clam-shell fashion.

The elongate base member 212 is shown in FIGS. 2, 3, and comprises a generally arcuate-shaped elongate base body 213 with tapered ends 214. It is to be noted that the tapered ends 214 may have an elliptical profile when viewed from the side or alternatively, may have cone-shape tapers with straight lines from their proximal to distal ends. The tapers may depend from the longitudinal axis by an angle from the range of about 20° to about 75°. Two pairs of orifices 220 defined by side walls are machined through the elongate base body 213 to reduce the weight of the elongate body 213 while maintaining its structural integrity and durability. The outward-facing inner surface of the elongate base body 213 has two or more sets of knurled projections 224 and/or ridged projections (not shown in FIGS. 14 and 15, but may be similar to those shown in FIGS. 1B, 2B, and 3A) and extending therefrom, wherein each set of knurled projections 224 partially extends inward from each end of the elongate base body 213. The set of knurled projections 224 may comprise repeating conical projections, spherical projections, spheroid projections, ellipsoid projections, pyramidal projections, and the like. The height of the knurled projections 224 extending outward from the inner surface of the elongate base body 213 may be 1 mm, 2mm, 3mm, 4 mm, 5 mm, and may extend outward to about 10 mm if so desired. Those skilled in this art will understand that the greater the height of the knurled projections 224, a greater clamping/gripping force will be applied by the combination guard and centralizer devise 200 when it is engaged and secured about a downhole tubing string.

One elongate edge of the elongate base member 212 may have a pair of hinge-pin housing elements 248 b at each end of the elongate base body 213 with a bore therethrough each of the pair of hinge-pin housing element 248 b for receiving therethrough a hinge pin.

The complementary elongate upper member 240 comprises a generally arcuate-shaped elongate upper body 242 with tapered ends 244. Three pairs of matching orifices 246 are machined through the opposite sides of the elongate upper body 242 to reduce the weight of the elongate upper body 242 while maintaining its structural integrity and durability. The three pairs of orifices 246 substantially reduce the weight of the weight of the elongate upper body 242 while maintaining its structural integrity and durability. The inward-facing inner surface of the elongate upper body 242 is provided with an outward projecting compression pad 285 position approximately in the middle of the elongate upper body 242 between its outer longitudinal edges and its ends. The purpose of the outward projecting compression pad 285 is to cooperate with the outward extending knurled projections 224 from the inner surface of the elongate base member 212 when the combination guard and centralizer devise 200 is used to encircle and engage a downhole tubing string to stably and securely engage the downhole tubing string so that the combination guard and centralizer devise 200 does not slip and slide down the tubing string when the tubing string is in operation.

A plurality of longitudinally extending channels may be provided within the inward-facing surface of the elongate upper body 242 thereby providing a contoured inner surface. For example, this embodiment has three side-by-side channels 252, 254, 526 wherein the center channel 252 is configured to receive and retain therein an electrical cable for providing power to an ESP. Channels 254, 256 on either side of channel 252 have narrower diameters and profiles that are suitable for receiving and retaining therein one or more cables communicating with sensors or instruments, or alternatively, for receiving and retaining there in a hydraulic line.

The elongate edge of the elongate upper body 242 opposite the side with the hinge-pin housing elements 248 a, 248 b, has two channels 250 extending vertically therethrough with one channel 250 located near each end of the elongate upper member 240. Each channel 250 is provided with a self-retaining bolt assembly 270 similar to the self-retaining bolt assembly 70 previously described in reference to FIG. 6.

One elongate edge of the elongate upper member 240 is provided with a pair of hinge-pin housing elements 248 a at each end of the elongate upper body 240 with a bore therethrough each of the pair of hinge-pin housing element 248 a for receiving therethrough a hinge pin. The pair of hinge-pin housing elements 248 a at each end of the elongate upper body 240 are complementary to and cooperable with the pair of hinge-pin housing elements 248 b at each end of the elongate base body member 212. Each set of complementary hinge-pin elements 248 a, 248 b are cooperable with a hinge pin 249 inserted through the bores provided therefore in the complementary hinge-pin elements 248 a, 248 b.

The opposite elongate edge of the elongate upper member 240 is provided with a pair of spaced apart feet 280

The combination cable guard and centralizer device 200 disclosed herein may be assembled by aligning the pairs of hinge-pin housing elements 248 a, 248 b on the elongate upper member 240 and the elongate lower member 212 respectively, and then inserting a hinge pin 249 in through the bores provided therefore in each pair of hinge-pin housing elements 248 a, 248 b thereby enabling a clam-shell type opening and closing of the combination cable guard and centralizer device 200 as illustrated in FIGS. 14A, 14B. When the elongate upper member 240 and the elongate base member 212 are in a closed position (FIG. 14B), the self-retaining bolt assemblies 270 may be swiveled into channels 250 so that the built-in washers of the bolt heads 270 positioned over shoulders provided therefore in channels 250 (FIG. 5A). The bolt components of the self-retaining bolt assemblies 270 may then be rotationally threadably engaged with the female-threaded bores of the cylindrical rod elements of the self-retaining bolt assemblies 270 to securely engage the elongate upper member 240 and the elongate lower member 212. It is to be noted that when the elongate upper member 240 and the elongate base member 212 are in a closed position and their elongate edges opposite their edges with the complementary hinge-pin elements are engaged and securely tightened with the self-retaining bolt assemblies 270, the pair of feet provided on the opposite elongate edge of the elongate upper member 240 are engaged with the opposite elongate edge of the elongate base member 212, thereby preventing potential pinching and/or crushing of cables and/or conduits that are being secured within the space between the combination cable guard and centralizer device 200 and the downhole tubing string as the self-retaining bolt assemblies 270 are being tightened. 

1. A combination cable guard and centralizer device for demountable engagement with a downhole tubing string, comprising: an arcuate-shaped elongate base member having tapered ends, a first outer surface, a first inner surface, a first elongate edge of the base member having a first pair of hinge-housing elements with bores therethrough wherein each of said first pair is at one end of the first elongate edge, and an opposite first elongate edge having a first pair of spaced-apart channels for receiving and demountably engaging therein each of said first pair of spaced-apart channels one end of a self-retaining bolt assembly, and wherein said arcuate-shaped elongate base member has a matching pair of spaced-apart orifices therethrough, and wherein said first inner surface has a set of outward-extending knurled projections projecting inward from each end of the arcuate-shaped elongate base member; a complementary arcuate-shaped elongate upper member having tapered ends, a second outer surface, a second contoured inner surface, a second elongate edge with a second pair of hinge-housing elements with bores therethrough wherein each of said second pair is at one end of the second elongate edge wherein the second pair of hinge-housing elements is complementary to and cooperable with said first pair of hinge-housing elements, and an opposite second elongate edge having a second pair of spaced-apart channels complementary to the first set of spaced-apart channels for receiving and demountably engaging therein the other end of the self-retaining bolt assembly, and wherein said arcuate-shaped elongate upper member has a matching pair of spaced-apart orifices therethrough, and wherein said second inner surface has at least two longitudinal channels extending therethrough for engaging cables or conduits therein; and a hinge pin interconnecting each pair of complementary first hinge-housing elements and the second hinge-housing elements.
 2. The combination cable guard and centralizer device of claim 1, wherein the arcuate-shaped elongate base member has two or more matching pairs of spaced-apart orifices therethrough.
 3. The combination cable guard and centralizer device of claim 1, wherein the arcuate-shaped elongate upper member has two or more matching pairs of spaced-apart orifices therethrough.
 4. The combination cable guard and centralizer device of claim 1, wherein the opposite second elongate edge of the arcuate-shaped elongate upper member has a pair of feet extending therefrom, said pair of feet provided for engagement with the opposite first elongate edge of the arcuate-shaped elongate base member.
 5. The combination cable guard and centralizer device of claim 1, wherein the inner surface of the arcuate-shaped elongate upper member is provided with a centrally positioned outward projecting compression pad projecting therefrom.
 6. The combination cable guard and centralizer device of claim 1, wherein the set of outward-extending knurled projections on the first inner surface of the arcuate-shaped elongate base member extends from one end to the other end of the arcuate-shaped elongate base member.
 7. The combination cable guard and centralizer device of claim 1, wherein the set of outward-extending knurled projections consists of a plurality of repeating conical projections, a plurality of repeating spherical projections, a plurality of repeating spheroid projections, a plurality of repeating ellipsoid projections, or a plurality of repeating pyramidal projections.
 8. The combination cable guard and centralizer device of claim 1, wherein the set of outward-extending knurled projections consists of a plurality of repeating ridges.
 9. The combination cable guard and centralizer device of claim 1, wherein the first inner surface of the arcuate-shaped elongate base member is provided with a second set of outward-extending knurled projections projecting inward from each end of the arcuate-shaped elongate base member.
 10. The combination cable guard and centralizer device of claim 9, wherein the second set of outward-extending knurled projections on the first inner surface of the arcuate-shaped elongate base member extends from one end to the other end of the arcuate-shaped elongate base member.
 11. The combination cable guard and centralizer device of claim 9, wherein the second set of outward-extending knurled projections consists of a plurality of repeating conical projections, a plurality of repeating spherical projections, a plurality of repeating spheroid projections, a plurality of repeating ellipsoid projections, or a plurality of repeating pyramidal projections.
 12. The combination cable guard and centralizer device of claim 9, wherein the second set of outward-extending knurled projections consists of a plurality of repeating ridges.
 13. The combination cable guard and centralizer device of claim 1, wherein the second inner surface of the arcuate-shaped elongate upper member is provided with a set of outward-extending knurled projections projecting inward from each end of the arcuate-shaped elongate base member.
 14. The combination cable guard and centralizer device of claim 13, wherein the set of outward-extending knurled projections on the first inner surface of the arcuate-shaped elongate base member extends from one end to the other end of the arcuate-shaped elongate base member.
 15. The combination cable guard and centralizer device of claim 13, wherein the set of outward-extending knurled projections consists of a plurality of repeating conical projections, a plurality of repeating spherical projections, a plurality of repeating spheroid projections, a plurality of repeating ellipsoid projections, or a plurality of repeating pyramidal projections.
 16. The combination cable guard and centralizer device of claim 13, wherein the set of outward-extending knurled projections consists of a plurality of repeating ridges.
 17. The combination cable guard and centralizer device of claim 1, additionally comprising a compressible collar affixed to an inner-facing surface of the elongate upper member.
 18. A compressible collar having a contoured outward-facing surface for mating engagement with the contoured inner surface of the elongate upper member of the combination cable guard and centralizer device of claim
 1. 